Wave guide antenna with bisectional radiator



April 14, 1953 L. c. VAN ATTA 2,635,189

WAVE GUIDE ANTENNA WITH BISECTIONAL RADIATOR Filed Sept. 14, 1945 2SHEETSSHEET 1 INVENTOR.

LESTER C. VAN ATTA ATTORNEY April 14, 1953 L. c. VAN ATTA 2,635,189

WAVE GUIDE ANTENNA WITH BISECTIONAL RADIATOR Filed Sept. 14, 1945 2S1-iEETS--SHEET 2 IN V EN TOR.

LESTER C. VAN ATTA Q/Ww 2 4 M.

ATTOR NEY I5 of wave guide II). has an aperture I4 therethroughcorresponding Patented Apr. 14,, 1953 WAVE GUIDE ANTENNA WITHBIsEc'rIoNAL RADIATOR I Lester C. Van Atta, Winchester, Mass., assignor,by mesne assignments, to the United States of America as represented bythe Secretary of War 7 I Application September 14, 1945, Serial No.616,369

7 Claims; (01. 250-.33 .63)

This invention relates to antennas for high frequency communicationsystems and particularly to radiating elements of the slot or dipoletype fed by an enclosed transmission line such as a hollow pipe waveguide or coaxial conductor.

It is the principal object of this invention to provide a novelradiating element adapted to radiate electromagnetic waves of energywith higher powers andover a greater bandwidth than heretoforeobtainable with the conventional slot radiators or conventional dipoleradiator.

It is another object of the invention to provide a novel radiatingelement of smoothly curved conformation adapted to eliminatediscontinuities,corners and critical dimensions, which disadvantages areinherent in dipole or slot radiators as heretofore known.

For a better understanding of the invention together with other andfurther objects thereof,

reference is had to the following description,

'ment of Fig. 3;

Fig. 5 is a perspective view of a slot type radiating element accordingto further-embodiment of the present invention; and Fig. 6 is alongitudinal sectional view of the radiating element of Fig. 5. I

Referring now to Figs. 1 and 2, I designates a wave guide generally ofrectangular cross-section adapted to transmit energy in the suitablemodes from a source not shown. A novel radiating element according tothis invention is generally designated II and comprises two sections ofa dipole, these sections being indicated by I2 and I3. j Section I2comprises a gradually flared leaf-like member having a circular base I4connected to and mounted on one of the broad walls Circular base portionI4 to an opening in wall I5 for receiving and permitting passage of theneck or stem portion I6 of the radiating element I3. I

Radiating element I3 is also leaf-shaped and has a neck or stem portionI6 extending through 2 aperture I 4' in circular base portion I4 of"element I2 and terminating in an enlarged base portion I1, is connectedto and in contact with the inner surface of broadwall I8 of wave guideI6 opposite to broad wall I5.

The broad leaf-like portions of elements 12 and I3 have their planesgenerally parallel to the broadwall I5 of wave guide I0 and are disposedin opposite directions longitudinallyof wave guide I6. The distance a:between the extreme edge portions ofelements I2 and I3 is preferablyapproximately one-half the wavelength or more of the radiant energy atthe desired frequency of operation and the height of the broad leaf-likeportions of each of elements I2 and I3 above wave guide III ispreferablya quarter wavelength, or less, which permits the wave guide Ii! to serve as a reflecting surface for the dipole radiating elements I2and I3. The gradual change of form and dimension of radiating elementsI2 and I3 serves to increase both the power handling capacity and theband width of the power radiating element II. The base portion I! ofelement I3 picks up energy propagated within wave guide III which iscarried through the neck portion I6 into the broad leaflike portions ofelement I3. It will thus be seen that radiating element II comprises auniform and gradually flared dipole center fed from opposite walls ofwave guide II] by means of base portions I l and I1. Base portion Ilmay, if

- desired, be shaped in the standard door-knob -Dipole radiating elementcomprises a substantially circular base 2I mounted on andconnected toone of the broad walls of wave guide 22. From the circular base 2| thereextend upwardly two flaring leaf-like dipole sections 23 and 24 ofuniform and gradual conformation extending in opposite directions fromthe approximate periphery of base portion 2I so that the broad leaf-likeend portions 25 and 26 have their planes substantially parallel with thebroad wall of wave guide 22. p

Extending through aperture 2! in the base portion 2I through acorresponding opening in the wall of said wave guide and into the regionof propagation within wave guide 22 is a probe 28 of any desired andsuitable design adapted to pick up energy propagated within wave guide22. Probe 28 extends upwardly through the base portion 2! and curvessmoothly toopen through a flared end portion 29 near the edge ofleaf-like portion 26. The flared end portion 29 serves to feed energy tothe leaf-like portion 26 and thus to excite the dipole radiating element20.

The diameter of the circular base portion 2| is preferably approximatelyoneto two-tenths of the wavelength of the energy at the desiredfrequency .of .operation and the dimension n: between the extremities:of portions 25 and 26 is approximately one-half wavelength as in thecase of Fig. 1. Probe 28 may, if desired, be adjustable as to depth ofpenetration into waveguide 22 to control the power output to radiating:iiipo'le :ele-' .vided in one of its walls with a transversely, in

cludin if desired, a diagonally, arranged slot 3| which may serve asahalf wave slot radiator of conventional design. Connected along each ofthe longitudinal edges of slot 3 are radiating plates 32 .and 33comprising substantially flat sheets of electrically conductivematerialhaving their edges along the edges of slot'3'l ben'tso that :theplanes of plates .32 and 33 are substantially parallel to I the broadwall-of waveguideBll. .Thus, plates 32 and 33 .areconnected along one oftheir edges'to the opposite edge portions of slot 3| and :then

bent away from each other so that they are in alignment and their commonplane is parallel to the broad wall .of wave guide '30. Preferably the.distance .zc between the extreme ,free edges of plates .32 .and 3,3 isapproximately half a wavellength and the distance .11 between the plates32 and 3.3 at their free edges .and wave guide 30 is preferably lessthan a quarter wavelength. In seffect, plates .32 and 33 may bedimensioned .so that their overall dimensions form a square conductingplane one-half wavelength on edge which is adapted .to be excited by theradiation through slctBJ and act as .a dipole radiating element.

Theradiatin elements, as shown and described hereinbefore with referenceto the several figures in the drawings, have been .capable of having aigreater power handling capacity and are effective over a greater bandof frequencies than dipole or slot radiating elements heretofore used.

While the invention has been herein described with reference to arectangular wave guide for feedin energy to the radiating element, itwill be understood that the invention is not limited to this particularstructure. elements according to the invention may .be

Instead the radiating mounted on and coupled to a :hollow pipe wave.guide .of any desired cross-section or a coaxial conductor along thelength or ,at the ends thereof.

While there has been described what is at present considered thepreferred embodiments of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the invention.

What is claimed is:

1. An antenna for high frequency communication systems includingarectangular hollow pipe wave guide for transmission of waves ofelectromagnetic energy, a radiating element coupled to I the energy insaid Wave guide, said element comprising two leaf-likesections extendingoutwardly from one of the walls of said wave guide, saidsections beingbent away from each other substantially parallel to the longitudinalaxis of said Wave guide toward opposite ends of said wave guide in sucha manner that their planes are in substantial alignment andsubstantially parallel to said wall of said wave guide.

2. An antenna as claimed in claim 1 wherein thedistancebetweenopposite-extremities between each section are approximately half thewavelength of the energy at the desired frequency of operation andwherein the distance from each of said extremities to the adjacent wallof said wave guide is no more than a quarter wavelength of said energy.

3. .An antenna :as claimed in claim 1 in which saidelement comprises adipole, one of the dipole iSBfitiQIIS comprisin a substantially circularbase having an aperture therein, said base being mounted on one of thebroad walls of said wave guide, .said one section being leaf-like inshape and extending gradually and uniformly away drom saidbase and saidWaveguide, the othe pne of said sections comprising a base connected tothe surface or the other broad wall o'fsaidw'ave guide, a neck portionextending to said "base through said aperture, and auniformlyandgradually flaring portion connected to the said neckportion, the free ends of said leaf-like portions extending in oppositedirections longitudinally of .said wave guide with their planessubstantially parallel with the broad wall of said waveguide.

a. An antenna as claimed in claim 1 wherein said elementcomprises adipole, said two dipole sections comprise a substantially circular basehaving an aperture therein connected .to one or the broad walls of saidwave guide and gradually flaring leaf-like portions extending .from saidbase away from said wall and longitudinally away from said waveguide,.said wall having an opening therein corresponding to saidaperturauand wherein a probe is disposed in a region of propagationinsaid Wave guide, amember connected to said probe and extending throughsaid opening and through said aperture andalong the general conformationof on of said dipole sections, said 0 member terminating in a flared endportion adjacent the extremity of one of said sectionssaid memberbeingadapted to transmit energy picked up by said probe to said onesection wherebyisaid radiating element is excited by said energy.

5. An antenna as claimed in claim 1 wherein the wave guide has aradiating slot-disposed transversely in one of the walls thereof, andwherein each of said dipole sections comprises substantially rectangularplate members, each plate-member being connected along one of theiredges to opposite longitudinal edges of said slot.

6. An antenna as claimed in claim l-wherein said element comprises adipole, said twodipole sections comprise a substantially circular basehavin an aperture therein connected to one of the broad Walls of saidwave guide and gradually flaring leaf-like portions extending from 'saidbase away from said wall and longitudinally away from said wave guide,said wall having an opening therein corresponding to said aperture, andwherein a probe is disposed in a region of propagation in said waveguide, a member'connecte'd to said probe and extending through saidopening and through said aperture and along the'general conformation ofone of said dipole section's, said member terminating in a flared endportion adjacent the extermity of one of said sections, said memberbeing adapted to transmit energy picked up by said probe to said onesection where by said radiating element is excited by said energy, andwherein said circular base has a diameter of between one-tenth andtwo-tenths of a wavelength of said energy at the desired frequency ofoperation.

7. An antenna as claimed in claim 1 wherein the wave guide has aradiating slot disposed transversely in one of the walls thereof,wherein each of said dipole sections comprisessubstantially rectangularplate members, each plate member being connected along one of theiredges to opposite longitudinal edges of said slot, and wherein saidrectangular sections together form a square each of wnose edges equalsapproximately onehalf of a Wavelength of said energy at the desiredfrequency of operation.

LESTER C. VAN ATTA.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Southworth July 9, 1940 Usselman Mar. 11, 1941 King Mar. 4,1947 Masters Nov. 4, 1947 Johnson et a1 Dec. 30, 1947 Masters Aug. 30,1949 Buchwalter et a1. June 20, 1950

